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Abstract:

A method for operating a hearing apparatus includes determining feedback
events, in which feedback suppression responds and/or in which feedback
is detected above a predeterminable feedback threshold value, determining
a frequency of the feedback events within a predeterminable duration and
emitting a signal if the determined frequency exceeds a predeterminable
frequency threshold value. A time instant for changing an earmold which
is no longer optimally positioned and is the cause of a frequent feedback
can therefore be advantageously predicted in a timely manner. A computer
program product for implementing the method and a hearing apparatus with
acoustic feedback suppression and/or acoustic feedback identification,
are also provided.

Claims:

1. A method for operating a hearing apparatus having at least one of
feedback suppression responding upon occurrence of an acoustic feedback
or acoustic feedback identification, the method comprising the following
steps:determining feedback events in which at least one of the feedback
suppression responds or feedback is detected above a predeterminable
feedback threshold value;determining a frequency of the feedback events
within a predeterminable duration; andoutputting a signal if the
determined frequency exceeds a predeterminable frequency threshold value.

2. The method according to claim 1, wherein the frequency threshold value
is less than a predeterminable acceptance value, and the frequency
threshold value is determined from an interpolation of the acceptance
value.

3. The method according to claim 2, which further comprises implementing
the interpolation with the aid of a frequency distribution of the
feedback events as a function of time, and extrapolating the frequency
distribution up to the acceptance value.

4. The method according to claim 3, which further comprises determining an
acceptance time instant on a basis of a curve of a frequency with which
the acceptance value is reached.

5. The method according to claim 1, which further comprises emitting the
signal acoustically or optically.

6. A computer software product stored on a memory executable by a control
unit to perform the steps according to claim 1.

7. A hearing apparatus, comprising:at least one of a feedback suppression
unit responding upon occurrence of an acoustic feedback or an acoustic
feedback identification unit;an event unit for determining feedback
events in which at least one of the feedback suppression responds or a
feedback above a predeterminable feedback threshold value can be
detected;a computing unit for determining a frequency of the feedback
events within a predeterminable time period; anda signal unit for
emitting a signal if the determined frequency exceeds a predeterminable
frequency threshold value.

8. The hearing apparatus according to claim 7, wherein the frequency
threshold value is less than a predeterminable acceptance value, and said
computing unit is configured for determining the frequency threshold
value from an interpolation of the acceptance value.

9. The hearing apparatus according to claim 8, wherein the interpolation
in said computing unit can be implemented on the basis of a frequency
distribution of the feedback events as a function of time, with the
frequency distribution being extrapolated up to the acceptance value.

10. The hearing apparatus according to claim 9, wherein said computing
unit is configured for determining, with the aid of a curve of the
frequency, an acceptance time instant at which the acceptance value is
likely to be reached.

11. The hearing apparatus according to claim 7, wherein said signal unit
is configured for outputting the signal acoustically or optically.

12. The hearing apparatus according to claim 7, which further comprises a
remote controller for emitting the signal.

13. The hearing apparatus according to claim 7, wherein the hearing
apparatus includes an in-the-ear hearing device.

[0002]The invention relates to a method for operating a hearing apparatus
with feedback suppression which responds upon occurrence of an acoustic
feedback and/or an acoustic feedback identification. The invention also
relates to a computer program product with a computer program having
software for implementing a method according to the invention, if the
computer program is executed in a control unit. The invention further
relates to a hearing apparatus with a feedback suppression unit which
responds upon occurrence of an acoustic feedback and/or an acoustic
feedback identification unit.

[0003]If couplings exist in a signal processing system of a hearing
apparatus between inputs and outputs (e.g. acoustic, electromagnetic,
electric, magnetic, etc.), feedback effects may occur. One example of
such a configuration is a hearing device 1 reproduced in schematic and
block form in FIG. 1. The hearing device can reproduce a digital system
10, which is located in acoustic surroundings. An incoming acoustic
signal 9 is recorded by a microphone 2 of the hearing device 1. The
recorded signal 9 is, inter alia, amplified in a signal processing unit 6
and output again by way of a receiver 3. An acoustic coupling from the
receiver 3 back to the microphone 2 takes place by way of a physical
feedback path 4. The recorded signal 9 is therefore formed of the total
of an incoming useful signal 8 and the signal by way of the feedback path
4. As a result of the feedback, feedback whistling occurs if both the
amplitude and also the phase condition are fulfilled. Sound artifacts
nevertheless already occur if the above conditions are only approximately
fulfilled.

[0004]In order to suppress the feedback effects, a method is known in
which the physical feedback path 4 is reproduced digitally. The
reproduction takes place through the use of an adaptive filter 5, which
is supplied by the receiver signal. After filtering in the adaptive
compensation filter 5, the receiver signal is subtracted from the
microphone signal in an adder 7.

[0005]Two paths therefore exist in the system, on one hand the physically
existing feedback path 4 and on the other hand the digital compensation
path reproduced by way of the adaptive filter 5. Since the resulting
signals of the two paths are subtracted from one another at the input of
the device, the effect of the physical feedback path 4 is ideally
cancelled.

[0006]In the case of a hearing device, an acoustic feedback is
substantially influenced by the fit accuracy of an earmold located in the
auditory canal. With a poor fit, sound waves can pass through the earmold
to a hearing device microphone and therefore generate unwanted feedback.
The form of the auditory canal, for instance size, curvature, condition,
is subject to temporal changes, for instance in the case of children
during growth or adults as a result of the changes to the connective
tissue of the ear. That results in custom-made ear molds no longer
ensuring adequate fit accuracy after a certain period of wear and
acoustic feedback occurring more frequently as a result.

[0007]The acoustic feedback is suppressed in modern hearing devices
through the use of signal processing (feedback cancellation). That
electronic measure only takes effect if feedback already occurs. Feedback
suppression methods also include a physically determined limit. In the
initial fit accuracy stage of the earmold piece, the feedback suppression
method is very reliable. A hearing device wearer only then seeks a
hearing device acoustician if the hearing device produces feedback
frequently or continuously. In particular, for those in need of care and
children, who possibly communicate with more difficulty, that behavior of
the hearing device is unsatisfactory.

SUMMARY OF THE INVENTION

[0008]It is accordingly an object of the invention to provide a method for
operating a hearing apparatus, a computer program product for
implementing the method and a hearing apparatus with feedback
suppression, which overcome the hereinafore-mentioned disadvantages of
the heretofore-known methods, products and apparatuses of this general
type.

[0009]With the foregoing and other objects in view there is provided, in
accordance with the invention, a method for operating a hearing apparatus
with feedback suppression, which responds upon occurrence of an acoustic
feedback and/or an acoustic feedback identification. The method comprises
the following steps:

[0010]determining feedback events, in which the feedback suppression
responds and/or in which a feedback is detected above a predeterminable
feedback threshold;

[0011]determining the frequency of the feedback events within a
predeterminable time duration; and

[0012]outputting a signal if the determined frequency exceeds a
predeterminable frequency threshold.

[0013]This is advantageous in that a time instant for changing an earmold
which is no longer optimally positioned in the ear canal and is the cause
of a frequent feedback can be predicted in a timely manner.

[0014]In accordance with another mode of the invention, the frequency
threshold value is less than a predeterminable acceptance value, with the
frequency threshold value being determined from an interpolation of the
acceptance value. As a result, a robust estimation of the achievement of
the acceptance threshold is possible.

[0015]In accordance with a further mode of the invention, the
interpolation can be performed with the aid of a frequency distribution
of the feedback events as a function of time, with the frequency
distribution up to the acceptance value being extrapolated. This
advantageously provides for a simple prediction as to when the acceptance
value is likely to be achieved.

[0016]In accordance with an added mode of the invention, the method
includes determining an interaction time instant on the basis of the
curve of the frequency, during which the acceptance value is probably
achieved.

[0017]In accordance with an additional mode of the invention, the signal
can be emitted acoustically or optically. As a result, a simple and clear
communication to the user or person caring for a user is ensured.

[0018]With the objects of the invention in view, there is also provided a
computer program product with a computer program, comprising software for
implementing the method according to the invention, if the computer
program is executed in a control unit.

[0019]With the objects of the invention in view, there is furthermore
provided a hearing apparatus with a feedback suppression unit, which
responds upon the occurrence of an acoustic feedback and/or an acoustic
feedback identification unit. The hearing apparatus comprises:

[0020]an event unit for determining feedback events, in which the feedback
suppression responds and/or in which a feedback can be detected above a
predeterminable feedback threshold value;

[0021]a computing unit for determining the frequency of the feedback
events within a predeterminable time period; and

[0023]In accordance with another feature of the invention, the frequency
threshold value is less than a predeterminable acceptance value, with the
frequency threshold value being determinable from an interpolation of the
acceptance value in the computing unit.

[0024]In accordance with a further feature of the invention, the
interpolation can be implemented in the computing unit with the aid of a
frequency distribution of the feedback events as a function of time, with
the frequency distribution being extrapolated up to the acceptance value.

[0025]In accordance with an added feature of the invention, the computing
unit can determine an interaction time instant, in which the acceptance
value is likely to be achieved, with the aid of the curve of the
frequency.

[0026]In accordance with an additional feature of the invention, the
signal can be emitted acoustically or optically through the use of the
signal unit.

[0027]In accordance with yet another feature of the invention, the hearing
apparatus can include a remote controller, with the signal being
emittable by way of the remote controller.

[0028]In accordance with a concomitant feature of the invention, the
hearing apparatus can also include an in-the-ear hearing device.

[0029]Other features which are considered as characteristic for the
invention are set forth in the appended claims.

[0030]Although the invention is illustrated and described herein as
embodied in a method for operating a hearing apparatus, a computer
program product for implementing the method and a hearing apparatus with
feedback suppression, it is nevertheless not intended to be limited to
the details shown, since various modifications and structural changes may
be made therein without departing from the spirit of the invention and
within the scope and range of equivalents of the claims.

[0031]The construction and method of operation of the invention, however,
together with additional objects and advantages thereof will be best
understood from the following description of specific embodiments when
read in connection with the accompanying drawings.

[0033]FIG. 2 is a diagram showing the frequency of feedback events; and

[0034]FIG. 3 is a plan view of an in-the-ear hearing device according to
the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0035]Referring now to the figures of the drawings in detail and first,
particularly, to FIG. 2 thereof, there is seen a diagram of a frequency H
of feedback events as a function of a time T, with the aid of which the
method according to the invention will be graphically explained. A
hearing apparatus with feedback suppression or feedback identification is
needed. A feedback event may be a response of the feedback suppression or
an identification of a feedback above a predeterminable feedback
threshold value. In accordance with the invention, these events are
counted and the frequency thereof HP is determined in a predeterminable
time period. The time period can be a calendar day or, however, also only
an hour, for instance. The determined frequencies HP are thus determined
as a function of time, for instance the frequency per day or the
frequency averaged per day from the hour values.

[0036]The frequencies HP are approximated by a frequency curve HK. The
curve HK can also be extrapolated through a current day A, at which the
last current frequency value HA exists, with the aid of empirical values
or approximation methods. From a predeterminable frequency, a so-called
acceptance value AW, the hearing apparatus feeds back so frequently or
exceeds the predeterminable feedback threshold value so often, that it is
unacceptable for a wearer of the hearing apparatus.

[0037]A time instant AT, at which the acceptance value AW will probably be
reached, is determined as a result of the extrapolated curve HK. If the
frequency HP now reaches a predeterminable threshold value SW, a time
instant ST of which is some days or weeks before the time instant AT, a
signal or a display of a residual time RT before the acceptance value AW
is reached is output. The wearer of the hearing apparatus or his/her care
giver therefore knows that a person skilled in the art must shortly be
found in order to adjust the hearing apparatus.

[0038]FIG. 3 shows a hearing device 1 which can be worn in the ear, along
with its important components. A microphone 2, with a sound inlet opening
for recording an acoustic signal, converts the recorded acoustic signal
into an electrical signal. The electrical signal is fed to a signal
processing unit 6 for further processing and frequency-dependent
amplification purposes. The further processed and amplified signal is
finally converted back from an electrical signal into an acoustic signal
through the use of a receiver 3 and output into the auditory canal of a
hearing device wearer by way of a sound channel. A battery 14 is used to
supply power to the electrical components of the hearing device 1.

[0039]The hearing device 1 according to the exemplary embodiment can be
adjusted in terms of its transmission characteristics to different
hearing situations (e.g. "quiet environment," "conversation,"
"conversation in interference-prone surroundings," "car travel," etc.).
The selection takes place through the use of adjusting certain parameter
sets (hearing programs), which adjust the signal processing unit 6 to the
respective hearing situation. A pushbutton 13 is used to toggle between
the individual hearing programs.

[0040]As a further component, the hearing device 1 includes a transceiver
unit 15 with an antenna 16 for the wireless exchange of data with a
further hearing device for a binaural supply or with a remote controller
and/or with an audio transmitter unit.

[0041]In order to suppress feedback, the hearing device 1 has a feedback
suppression unit 20 and a feedback identification unit 21 in the signal
processing unit 6 for suppressing and/or identifying acoustic feedback.
If the fit accuracy of the hearing device 1 worsens over time, the
frequency of the feedbacks increases. With the aid of an event unit 22
connected to the feedback suppression unit 20 and the feedback
identification or recognition unit 21, the feedback events are
determined, in which the feedback suppression unit 20 responds and/or in
which the feedback identification unit 21 detects a feedback above a
predeterminable feedback threshold. The frequency of the feedback events
is determined within a predeterminable time period with a computing unit
23 connected to the event unit 22. If the determined frequency exceeds a
predeterminable frequency threshold value, an acoustic signal is output
through the receiver 3 by a signal unit 24 connected to the computing
unit 23. The signal can optionally also be output optically and/or
indicated to a remote controller of the hearing device 1 or displayed on
the hearing device 1 itself, for instance.

[0042]In the case of hearing device wearers in need of care, the
unpleasant consequences of hearing device feedback can thus be avoided by
promptly informing a care giver of the hearing device wearer about
changes to the feedback behavior, for instance. Thanks to an advance
warning, it is possible to promptly allow new ear molds to be
manufactured. A hearing device acoustician therefore need not take
excessively drastic measures in terms of eliminating feedback (e.g.
reducing the maximum amplification). When providing for children, it is
very critical for childhood development if adjustment changes are needed
specifically as a result of occurring feedbacks. The prediction according
to the invention reliably prevents this.